Suppose that the average score in a class before the final exam was 80%. The average score on the final exam was 85%. How does the marginal score (final exam average) affect overall grades? a) The marginal score lies below the average and overall grades fall. b) The marginal score lies above the average and overall grades rise. c) The marginal score lies below the average and overall grades rise. d) The marginal score lies above the average and overall grades fall.